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Home >> Volvo >> 2009 >> V70 >> Repair and Diagnosis >> Engine Performance >> Engine Control Systems >> Charging System, Electrical Control Modules, Engine Control Module (ECM) - Design And Function >> Forward Sensing Module (FSM) (2009-10) >> Diagnostic Functions >> Diagnostic Trouble Codes (DTCS)
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Diagnostic Trouble Codes (DTCS)

A diagnostic trouble code (DTC) is stored if the control module detects a fault.

A malfunction that has been detected repeatedly during several driving cycles will permanently turn off the functions adaptive cruise control, collision warning, and brake assistance as well as store a diagnostic trouble code for this.

A permanently switched off system can only be reactivated by resetting DTCs in the Forward Sensing Module (FSM), Central electronic module (CEM), Brake control module (BCM) in the same operating cycle.

A driving cycle includes ignition on, that the vehicle speed goes above 20 km/h as well as ignition off.

If a fault occurs in the functions for adaptive cruise control, brake support in the event of the collision risk and functions, a fault counter counts up per function. If these counters, regardless of each other, reach a predetermined value below one and the same operating cycle, independent error flags are set in the monitoring logistics in the Central electronic module (CEM).

Permanent switching off of the functions results in diagnostic trouble codes (DTCs) being stored in the Forward Sensing Module (FSM), Brake control module (BCM), and in the Central electronic module (CEM). The diagnostic trouble codes (DTCs) must be erased from all control modules during an operating cycle to reset these error flags.